Burn-resistant plastic compositions

ABSTRACT

Solid burn-resistant polymeric compositions are formed by reacting substances such as Cl(PNCl2)9PCl4 and (PNCl2)3 4 with epoxy resins to form PNCl2-epoxy pre polymers. These prepolymers are blended with orgainc liquid prepolymers such as phenolics, epoxies, polyurethanes and polyesters and the blends are cured to form fire resistant plastics, wherein initial P,N, and Cl contents are wholly retained. Those two components, i.e., PNCl2 component and epoxy resin are admixed with liquid organic prepolymers (and polymerization catalysts therefor) and the system is then cured, usually by heating, whereby the PNCl2-epoxy polymer is formed in situ along with the matrix polymer, or in some cases chemically bonded to the organic polymeric crosslinked plastic.

United States Patent [191 Frank et al.

[4 Feb. 18, 1975 BURN-RESISTANT PLASTIC COMPOSITIONS [73] Assignee: W. R. Grace & CO., New York,

22 Filed: Feb. 16, 1971 [21] Appl. No.: 372,701

Related U.S. Application Data [62] Division of Ser. No. 817,144, April 17, 1969, Pat.

[52] U.S. Cl. 260/47 EN, 260/2 P, 260/2 N,

260/2 EC, 260/18 PF, 260/47 EC, 260/59,

260/77.5 AR, 260/830 R, 260/830 TW,

[51] Int. Cl C08g 30/14 [58] Field of Search... 260/2 EP, 2 EC, 2 N, 47 EN, 260/47 EC, DIG. 24, 2 P, 59, 18 PF [56] References Cited UNITED STATES PATENTS 2,412,055 11/1968 Koral 260/834 3,372,208 3/1968 Waters et al. 260/830 TW 3,565,861 2/1971 White 260/47 OTHER PUBLICATIONS Handbook of Epoxy Resins Lee et a1. 1967 (p. 5-32: 5-37).

Primary ExaminerMelvin Goldstein Assistant Examiner-T. Pertilla Attorney, Agent, or 'FIIIfl-RICI18l'd P. Plunkett; Kenneth E. Prince ABSTRACT Solid burn-resistant polymeric compositions are formed by reacting substances such as C1(PNCl PCl and (PNCI with epoxy resins to form PNCl -epoxy pre polymers. These prepolymers are blended with orgainc liquid prepolymers such as phenolics, cpoxies, polyurethanes and polyesters and the blends are cured to form fire resistant plastics, wherein initial P.N, and Cl contents are wholly retained. Those two components, i.e., PNCl component and epoxy resin are admixed with liquid organic prepolymers (and polymerization catalysts therefor) and the system is then cured, usually by heating, whereby the PNCl epoxy polymer is formed in situ along with the matrix polymer, or in some cases chemically bonded to the organic polymeric cross-linked plastic.

2 Claims, NO Drawings BURN-RESISTANT PLASTIC COMPOSITIONS This is a division of application Ser. No. 817,144,

filed Apr. 17, 1969 and now U.S. Pat. No. 3,641,193.

BACKGROUND OF THE INVENTION 1. Objectives of the Invention An objective of this invention is to produce burnresistant polymeric compositions. Other objectives will be obvious to those skilled in the art from a reading of the following specification and claims.

2. Prior Art It has been reported that unsaturated alkyd resins have been treated with polyphosphonitrilic chlorides and styrene to supposedly improve the fire extinguishing properties. Partly or completely hydrolyzed or ammonolyzed polyphosphonitrilic chlorides are reported to be effective flame proofing materials.

BROAD DESCRIPTION OF THE INVENTION This invention encompasses a process for preparing a solid burn-resistant polymeric composition. The process includes admixing a material selected from the class consisting of (i) a cyclic (PNX where y is at least three and where X is a halogen atom, (ii) PX where X is a halogen atom, (iii) PX where X is a halogen atom, (iv) POX where X is a halogen atom and (v) linear X(PNX PX where y is at least one and where X is a halogen atom; a compound or resin containing at least two epoxy groups; an organic prepolymer which includes at least one monomer; and a poly merization catalyst for said organic prepolymer. The process further includes curing the prepolymer mixture system at a temperature between about and about 250C. The PNX material, etc., cures the epoxycontaining compound or resin when rates are not controlled by cooling. HX formed in the reaction is not released but is retained in the system via reaction with an epoxy or hydroxy group of the epoxy resin and thus enhances the fire resistance of the polymeric composition. The prepolymer mixture is simultaneously cured by the polymerization catalyst to form a flame-resistant polymeric composition. This process can be used to increase the flame-resistance of polymers with which the PNCl -epoxy composition is compatible. There may or may not be chemical bonding between the PNCl epoxy polymer and the other polymers in flameresistant polymeric compositions.

Preferably the PNCl -epoxy-containing compound and the organic prepolymer are liquid at the mixing and curing temperatures. The cyclo-PNC1 polymers are solid but form liquid mixtures with some of the epoxy resins. Preferably, basic accelerating materials are added to the formulations when linear or cyclic PNCl polymers are used.

This invention also encompasses the above process which is modified by separately preparing the solid PNCl- -epoxy polymer, reducing the polymer to small particles, and admixing the particles with either a Solid or liquid organic prepolymer and catalyst therefor. The prepolymer mixture is then cured.

The products of both of the above processes are encompassed within the scope of this invention.

DETAILED DESCRIPTION OF THE INVENTION Examples of polyphosphonitrilic chlorides which are useful as starting materials are: (PNCl m.p.=1 14C.; (PNCl m.p.=123.5C; (PNCl m.p.=40.5C to 2 41C; (PNCl m.p.= to 91C; (PNCl m.p.=8 to 12C; (PNCM m.p.=57 to 58C; (PNCl h etc. The mixture of (PNCI and (PNCI L, containing 60 to 70 mole percent of the trimer, has a m.p. of 885 to 89C and is also useful. This invention also cncompasses the use of other polyphosphonitrilic halides and mixed halides, such as (PNF m.p.=27.8C; (PNF- h, m.p.=30.4C; P N Cl fl; P N ClF P,N,Cl F,,, m.p.=21C; (PNBr m.p.=l9l.5C; P N BrCl can be used as starting materials in preparing the phosphonitrilic polymers having at least two reactive end groups.

The trimer and the tetramer of (PNCLQ have cyclic structures. (PNBr (PNF +(PNF also have cyclic structures. It is reported that the fluorides and chlorides up through (PNF and (PNCl have ring structures.

The polymeric phosphonitrilic chlorides (PNCl 11 are prepared by the reaction of phosphorus nitrides with chlorine, by heating phosphorus pentachloride with solid ammonium chloride at to C, by heating PCl and NH Cl in o-dichlorobenzene solution, or by other methods well known to those skilled in the art. A method for preparing an admixture of (PNCl 75 percent, and (PNCl 25 percent and separating the components, is given on page 229 of Gefter E. L., Organop/wsphorus Monomers and Polymers, associated Technical Services, Inc., N.J., (1962).

X[PNX ],,PX where y equals one to 45 and X is a halogen atom, is the general formula for the series of liquid linear polyphosphonitrilic halides. Preferably, the linear PNCl polymers have a molecular weight between 400 and 50,000. Examples of Cl[PNCl ,,PCl

It should be noted that linear polymers which have the formula:

are probably in the following form:

6| Cl l Cl-PN PNCl P-Cl l Yll Cl 0 after even brief exposure to the atmosphere.

As used herein, the terms polyphosphonitrilic halides and phosphonitrilic halide polymers encompass cyclic polymers of the class (PNX2)y, where y is 3 to 17 and X is a halogen atom, and linear polymers of the class X(PNX ),,PX,, where y is at least one and X is a halogen atom.

Useful examples of PX where X is a halogen atom are: PCl PBr PF P1 PF CI, PF Br, etc. Useful ex- 3 4 amples of POX where X is a halogen atom are; POCI er-epoxy resin reaction product components are added POF etc. Useful examples of PX where X is a halogen to polyester resins, cure does not readily occur without atom are: PCl PBr PCl PF Cl PF Br etc. the presence ofa basic accelerating material, e.g., N.N- An epoxy group is dimethyl aniline. Addition of linear PNCL polymer 5 must be carefully controlled to avoid an autoaccelera- F tive reaction which produces decomposition temperao tures.

Cyclic (PNCI or 4 polymer does not react with This invention includes materials termed epoxy resins l epoxy resins P to 165C HOWeVer, iffl q a e nary hyand epoxy compounds. ,This invention requires that droxide or salt (e.g., benzylphenyldimethylammonium those compounds have at least two epoxy groups so chloride or trimethylbenzylammonium hydroxide) is that p lym ric Structures Can be obtained. Liquid added in trace amounts, a cured epoxy resin results at epoxy compounds and resins are preferred. Examples 100 to 135C. Thus the uncured mixture of cyclic of useful epoxy resins are the reaction products of epi- PNClz p y and P Y resins Can be added I0 Other chlorohydrin with bisphenol A, the novolak resins, the uncured polymer systems (e.g., polye er phen li aliphatic glycols, and polyglycols, etc,; bis-p, p'hydroxpolyurethanes) and if quaternary ammonium salt or hyyphenyl sulfone; and so forth. droxide is present together with the usual curing agents The amount of cyclic or linear PNCl polymer, ete,, for the respective resin systems, the cure of the cyclic admixed with the epoxy resins should be a stoichiomethp y resin DCCUFS n s t during e Cure of e ric amount but can range from about 0.1 to ab ut two matrix resin, and a non-burning product results equivalent parts based upon an equivalent part of The materials to form the PNCb-epoxy reaction epoxy resin. Obviously a high degree of fire-resistance P t a added to the organic prepolymer system requires a high content of PNCl polymer. and catalyst therefore, so that an intimate admixture The reaction of the PNCI polymers, either cyclic or can be obtained by in situ formation of the epoxy rcaelinear, are postulated to react difunctionally in curing On product and the polymer. Preferably the organic the epoxy resin. When (PNCl is employed, the folprepolymer system and the materials to form the epoxy lowing reaction is thought to occur: reaction product are liquids at the mixing and curing l t CH; OH;

- cHloH-crn0Rn-ooH2olr-cHiotPNomotocHi-(JIkcHio-R,.-@-tb-@-tb-@-oom-cn-CH, W 31 31 43113 on; 0

where R is the parenthetical portion of one of the reactemperatures. The amount of materials (to form the tants in the above formula; or epoxy reaction product) in the mixture of the organic P -,N;;Cl resin (CHOH) ZHCl P N Cl, prepolymer system, catalyst therefore and said materi- (OCH): Resin als is within the range of about 15 to about 99 percent followed by by weight and preferably between about 20 to about 45 percent by weight.

7 The useful organic prepolymer systems include un- O cured epoxies, polyester prepolymers, polyamide prepolymers, phenolic prepolymers, polyurethane prepolymers, low melting ureaformaldehyde prepolymers,

5O melamine-HCHO prepolymers, polyimide prepolymers, ol carbonate re 0] mers, ol hen lcne or, finally one chlorine substituent of the (PNCl may Oxide i g etc. p p y p yp y react with an epoxy group and the second chlorine may I react with a hydroxy group. In any event no HCl should Various usfiful Polyester composltlons arc gll'cn be lost from the system, therefore the total firem the follflwmg p f p retardant value if the PNCI moieties is retained. The preferred unsaturated polymerizable mixtures to Similar reactions can occur between PNCl polymers be cured by the process of this invention Gconvenand epoxy novolac resins or simple phenoltional classes of resins known in the prior art. The most formaldehyde resins, polyurethanes, and between preferred polyester resins are prepared by the esterili- PNCI polymers and other resins containing active hy- 0 cation of alpha, beta-unsaturated polybasic acids, and

drogens. Also the PCI,,. PCI ctc., phosphorous crossdihydric alcohols. (ertain Compounds of this type may linking agents are visualized as reacting with active H be indicated generically as follows: compounds and epoxy groups. Epoxy compounds are M(iM(l--M-(i whcrc, --M- represents an particularly advantageous because of their HCl scavunsaturated dibasic acid residue and i-- represents enging ability. a dihydric alcohol residue. Modifying dihasic acids may Linear PNCL polymer will cure epoxy resins without also be used in the polyester resin compositions. Rcprc addition ofa basic catalyst, by heating the mixture, ususentativc dihydric alcohols and unsaturated polyhasic ally above C. However, when linear PNCl polymacids are shown below.

In preparing unsaturated polyesters which may be employed in the practice of the present invention, the alcohol component may comprise ethylene glycol, diethylene glycol or propylene glycol, or one of the group of solid polyethylene glycols designated as Carbowax. Polyethylene glycols such as the Carbowaxes are understood to have molecular weights above 300.

The acid component usually comprises an alpha, beta-ethylenically unsaturated polycarboxylic acid such as maleic, fumaric or itaconic acid, or the wellknown derivatives of these polycarboxylic acids having ethylenic unsaturation in alpha-beta relation to the carboxyl group. Polybasic acids such as aconitic acid, tricarballylic acid or citric acid may also be employed. A plurality of such acids also may be mixed with each other, if so desired. In many instances, it may be desireable to include a dicarboxylic acid free of ethylenic unsaturation. Examples of this latter type of dicarboxylic acid include phthalic acid or terephthalic acid, which although they contain double bonds in the benzene ring, do not undergo addition reaction with monomer compounds and may, therefore, be considered as being the equivalent of saturated compounds. Likewise, aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, or azelaic acid may be substituted for a part of the alpha, beta-ethylenically unsaturated dicarboxylic acid. The proportion of the non-ethylene acid with respect to the alpha, beta-ethylenically unsaturated acid is susceptible of wide variation. A molecular proportion of 0.25 to 12 moles of saturated acid per mole of unsaturated acid is usually used for commercial applications. Also acid anhydrides of these dicarboxylic acids can be used instead of the dicarboxylic acids.

Examples of ethylenically unsaturated monomers are:

l. Monoolefinic hydrocarbons, that is, monomers containing only atoms of hydrogen and carbon, such as styrene, alpha-methyl styrene, alpha-ethyl styrene, alpha-butyl styrene, vinyl toluene, and the like;

2. Halogenated monoolefinic hydrocarbons, that is,

monomers containing carbon hydrogen and one or,

more halogen atoms such alpha-chlorostyrene, alpha-bromostyrenc, 2,5-dichlorostyrene, 2,5- dibromostyrenc, 3,4-dichlorostyrene, 3,4- difluorostyrcne, ortho-, metaand para-fluorostyrencs, chlorocthylenc (vinyl chloride), l,l-dichloroethylcne (vinylidene chloride), and the like;

3. Estersof organic and inorganic acids such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate, vinyl caproate, vinyl cnanthate, vinyl benzoate, vinyl toluate, vinyl p-chlorobenzoate, vinyl-o-chlorobenzoate, vinyl p-methoxybenzoate, vinyl p-ethoxybenzoate, methyl methacrylate, ethyl methacrylate, methyl crotonate, ethyl crotonate, methyl acrylate, ethyl acrylate, hepty acrylate, octyl acrylate, isopropenyl propionate, isopropenyl benzoate, isopropenyl o-bromobenzoate, vinyl alphabromoacetate, vinyl alpha-chloropropionate, vinyl alpha-iodopropionate, allyl formate, allyl acetate, allyl chloroacetate, ally] chlorovalerate, methyl alphachloroacrylate, diallyl phthalate, and the like;

4. Organic nitriles such as acrylonitrile, methacrylonitrile, ethacrylonitrile crotonitrile, and the like; 5. Acid monomers such as acrylic acid, methacrylic acid, crotonic acid, 3-butenoic acid, angelic acid,

tiglic acid and the like;

6. Amides such as acrylamide, alpha-methyl acrylann ide, N-phenyl acrylamide, N-methyl-N-phenyl acrylamide, N-methyl acrylamide, and the like.

The preferred monomers are liquid compounds soluble in the polyester component. They will contain the C=CH group and preferably the latter will be attached to a negative radical such as a benzene ring. a chlorine atom, an ester linkage, a nitrile group or the like. They should be free of carbon-carbon conjugated double bonds.

The most preferred polyesters are the burn-resistant type wherein halogenated aromatic acid anhydrides or halogenated endomethylenecyclohexane dicarboxylic anhydrides are added as part of the dibasic acid moiety.

The curing time of the organic prepolymer systems varies between about 1 minute and about 24 hours. This time span depends, in part, upon the type of organic prepolymer system, the amount of catalyst, and so forth. The curing temperature for example of the polyester prepolymer systems varies between about 15C and about 250C.

The type of catalyst promotor which can be used in those systems is extensive. One of the promotor types which can be used in the polyester prepolymer systems is a cobalt salt which is capable of being dissolved in the resinous composition. Suitable soluble cobalt octoa te or any other higher fatty acid salt of cobalt. The amount of cobalt salt can be varied from about 0.001 to 0.3 percent of the salt calculated as dissolved metallic cobalt based on the total weight of the resin components, catalyst and promotor mixture employed. The vanadium promotors disclosed in US. Pat. No. 3,333,021 are useful. Another promoter type material is a variety of amine promoters. Suitable amine promoters are disclosed in US. Pat. No. 2,480,928.

The organic prepolymer systems of this invention can also contain other compatible additives, such as fillers (silica, carbon black, etc., dyes), reinforcing materials (asbestos, chopped glass fibers), etc.

As an alternative method the materials (preferably liquid) to form the epoxy reaction product can be admixed, cured, and reduced in size. The particles can then be admixed into the organic prepolymer system and catalyst therefore, which in turn is cured. The range of ingredients is the same as in the other method of preparation.

The term solution, as used herein, encompasses disperions, solutions, suspensions, colloids, etc.

The following examples will aid in explaining, but should not be deemed as limiting, the instant invention. In all cases, unless otherwise noted, all parts and percentages are by weight.

EXAMPLE l Two parts by wt. of liquid linear PNCl polymer [about 1100 average mol. wt. and represented by the formula {Cl(PCl =N)P(O)Cl was gradually added to 8 parts by wt. of Epon Resin 828 (Shell Chemical Co. product having about 200 equivalent weight per epoxy function) while stirring vigorously. Slow addition over 5 minutes prevented the temperature from rising above C. from heat of reaction. The mixture was then placed in an oven at C. and curing occurred overnight (16 hours). The cured product was non burning, i.e., after 30 seconds ignition, the resin selfextinguished within 2 or 3 seconds (ASTM D-635).

EXAMPLE 2 Example 1 was repeated except that the linear PNC1 polymer and Epon 828 were poured together and then stirred. The exothermicity of the reaction resulted in excessive temperatures and a run-away reaction. Only a black charred product remained.

EXAMPLE 3' Example 1 was repeated using parts by weight of the same batch of linear PNCl polymer and parts by weight of Epon Resin 828. The cured product was immediately self-extinguishing in the same buring test.

EXAM PLE 4 Example 1 was repeated using 10 gm. of the same PNCl polymer and 10 gm. of the same resin. The cured product was self-extinguishing in the burning test (ASTM-D635).

EXAMPLE 5 Example 4 was repeated except that the liquid prepolymer was not cured. The liquid was blended with a maleic-phthalic acid-glycol polyester (Clear Cast polyester, American Hanidcrafts Company, Ft. Worth, Texas) in the ratio of 40 parts (PNCl ),,-Epon liquid 60 parts of polyester resin. Curing was conducted by adding 1 percent methylethylketone peroxide catalyst (based on the weight of the mixed resins and additives), and 1 percent cobalt octoate solution (12 percent cobalt). Curing did not begin until 1 percent by weight of dimethylaniline was stirred in. After standing overnight, a rigid cure was obtained. The sample was selfextinguishing in one second by ASTM D-635.

EXAMPLE 6 Twenty parts by weight of linear (PNCI L, (end groups probably Cl and POCL were blended with 80 parts by weight of the same Clear Cast polyester employed in Example 5, The mixture required 1 part N,N- dimethyl aniline (DMA) (a basic material) and 3 parts by weight methylethylketone peroxide catalyst (50 percent active) and 1 part cobalt octoate solution for curing. The cured product was self-extinguishing and re tained considerable flexibility. It was immediately selfextinguishing after the 30 seconds ignition test.

EXAMPLE 7 Example 6 was repeated except that 10 parts of linear (PNCl and 90 parts Clear Cast polyester was used. A hard cured resin resulted which self-extinguished in the 10-second ignition test.

EXAMPLE 8 An example similar to 6 was run in an attempt to improve the rigidity and strength of the cured resin. Epon 828 (10 parts by weight) was admixed with 10 parts Clear Cast resin and'20 parts of (PNCl polymer as in Example 6, was stirred in to give a clear composition. When cured by the same peroxide-DMA-cobalt octoate formulation, as in Example 6, the resin was rigid after 24 hours, had high strength, and was flameresistant (self-extinguishing).

(Example 8 above, and Examples 9, 10, 11 and 12 represent in situ formation or curing ofthe linear polyphosphonitrilic chloride-epoxy resin reaction product in liquid prepolymers which are cured themselves and require compatible flame or burn-resistant Components.)

EXAMPLE 9 In a preparation similar to that of Example 6, parts by weight of cyclic (PNCl was used instead of the linear PNCl polymer (about 1100 mol. wt.). The cured product was flexible after 24 hours as was the cured product of Example 6. It was also self-extinguishing in one second after a -second ignition.

EXAMPLE 10 Product of Example 9 was too flexible and weak to be of value in certain applications, so a preparation was made to improve the rigidity and strength of the polyester composition of Example 9. 70 parts Clear Cast Resin, 20 parts cyclic-(PNCl polymer and 10 parts Epon Resin 828 were well mixed and were cured with the same formula as in Example 9, Le, 3 parts by weight of 50 percent methyl ethyl ketone peroxide, 1 part N, N-dimethylaniline and 1 part cobalt octaote solution (12 percent cobalt). After 24 hours a rigid cured clear green-tinted resin obtained. It was immediately self-extinguishing by the 30-second ignition test. (ASTM D-635).

EXAMPLE 1] 85 parts by weight of polyester resin (Clear Cast), 10 parts cyclic (PNCl polymer and 5 parts Epon 828 epoxy resin were combined and cured as in Example 10. The product after 24 hours passed the l5-second ignition test (self-extinguished). This example shows that more than 10 percent by weight of cyclic (PNCl is needed in plastic compositions for effective fire-resistance.

EXAMPLE 12 Example 11 was repeated except that 75 parts by weight of polyesterresin, 10 parts by weight of Epon 828 and 15 parts by weight of cyclic (PNCl polymers were used. The mixture was cured overnight, using the formula of Example 10. The product was selfextinguishing by ASTM D-635 test.

EXAMPLE 13 EXAMPLE 14 Example -1 3 was repeated except that the cyclic PNCl polymer was omitted. Curing occurred slowly at 135C. after initiation with the quaternary ammonium hydroxide solution. A good hard cure resulted in 18 hours. The product readily burned after 15 seconds ignition until the sample was completely consumed.

EXAMPLE l Fifteen parts by weight of Shell Epon Resin 828 was warmed to 90C. and 5 gm. of cyclic PNCl polymer mixture of triand tetra-phosphonitrilic chloride was stirred in. The mixture did not cure in 65 hours at 90C. The temperature was increased to 135C. for 4 hours. No cure occurred. Temperature was raised to 155C. for 16 hours. The mixture was still quite fluid. The mixture was cooled to 100C. and 0.1 part by weight of butanol was added. After 24 hours at 100C., no cure was obtained and 0.10 parts triethanolamine was added. After 4 hours at 125C. it was heated at 155C. for 18 hours. A hard clear cured sample was obtained which contained only percent PNCl additive; almost 3.5 parts by weight of the cyclic (PNCl lpolymer had sublimed out of the mixture. This cured resin was still self-extinguishing, burning for 10 seconds after a 30- second ignition by ASTM D-635 method. This example demonstrates that alcohol does not catalyze the cure of cyclic PNC1 polymer-Epon resin combination. A base is required to catalyze that combination.

EXAMPLE l6 Epon Resin 1001 (m.p. 64-76 C.) was weighed out in the amount of grams and melted. One gram of N, N-tetramethylenediamine was added for curing. The mixture was heated for 16 hours at 90C. and for 2.5 hours at 135C. The product was a clear strong resin which did not break when hurled against a marble bench top. The resin was classified as burning" in ASTM D-635 test since burning continued until the sample was completely consumed. This example demonstrated the action of the base in accelerating curing in the absence of the PNClg additive and demonstrated the need of the PNC1 additive.

EXAMPLE 17 Epon resin 828 (16.2 parts by weight) was admixed with 1 1:3 gm. of linear PNC1 polymer taking precautions not to allow the temperature of the reaction to exceed 60C. by very gradual addition of the linear PNCl polymer. About 11 parts by weight of this mixture were combined with 0.11 part by weight of trimethylbenzylammonium hydroxide as catalyst, which was found necessaary when cyclic PNCl polymers were reacted with epoxy resins. Nothing was added to the remainder of the mixture. Both samples were cured after heating for 1.5 hours at 200F. followed by heating for 2.5 hours at 275F. Both samples were immediately selfextinguishing by ASTM D635 test. This example shows that no catalyst is required for reaction and curing of linear PNC1 epoxy resin mixtures.

EXAMPLE 18 14.2 parts by weight of epoxy resin (Epon 828) were weighed into an aluminum pan. While stirring with a magnetic stirrer, 10.2 parts by weight of linear PNC1 polymer (having a molecular weight of about 1100 and represented by the formula [Cl(PCl =N)nP- =(O)Cl was added over a period of 10 minutes. The temperature rose to 60C. The liquid product (designated sample A) contained 42 percent linear PNC1 polymer.

To 20.9 parts by weight of Clear Cast polyester, 4.6 parts by weight of sample A were added. The mixture was stirred. The mixture (designated sample B) contained 1.9 parts by weight of 8.3 percent linear PNCl polymer. To sample B was added 1 part by weight of methylethylketone peroxide, 0.25 parts by weight of cobalt octoate solution l 2 percent cobalt). 0.4 part by weight of benzyltrimethylammonium hydroxide (added as 40 percent solution in methanol). and 1 part by weight N,N-dimethylaniline. The resultant mixture was stirred well at C. and then set aside to cure. After 40 hours, the sample was still flexible and soft. The cure was completed in 3 hours at about 200F. The product was self-extinguishing after 10 seconds ignition, but was classified as burning after 15 seconds ignition.

Twenty parts of Sample A was sprinkled with 0.2 parts by weight of benzyldimethylphenylammonium chloride and was placed in a 200F. oven for 3 hours. A hard cured sample resulted which proved to be immediately self-extinguishing after 30 seconds ignition. Thus 8 percent PNCl additive gives considerably less fire-resistance than desired. On the other hand, 42 percent PNCl additive in the epoxy resin is much higher than necessary for good flame resistance. Also, the cure can be accelerated with a quaternary salt.

EXAMPLE 19 EXAMPLE 20 The cyclic (PNCI was mixed with epoxidized Soya oil in the weight ratio of 9.55 parts to 9.3 parts. To the mixture was added with stirring 1.75 ml. of 40 wt. percent benzyltrimethylammonium hydroxide. After an hour of heating at C. the mixture was heated at 135C. for 3 hours. The cured product wasvery hard. By ASTM method D-635 the cured resin self-extinguished in less than 1 second after 30 seconds ignition.

EXAMPLE 21 25 parts by weight of the uncured mixture of Example 21 (cyclic PNCl polymer and epoxy resin) was blended with a parts by weight molten novolak resin at 100C. (The novolae resin was prepared by refluxing parts by weight of phenol, 92.4 parts by weight of 37 percent aqueous formaldehyde and 1 part by Weight oxalic acid dihydrate for 30 minutes; another part by weight of oxalic acid hydrate was then added and refluxing was continued for 1 hour; 400 parts by weight of water was added and the mixture was cooled and settled, the water layer decanted. and then vacuum distillation was used to remove water until 120C. pot temperature was reached). To the mixture was added 2.5 parts by weight of a 40 percent solution of benzyltrimethylammonium hydroxide. The mixture was cured by heating at C. for 1 hour. The cured product after 24 hours was self-extinguishing in ASTM D-635 tests.

EXAMPLE 22 To 19 grams of Epon 828 resin 2.1 gm. of PCI;, was added with stirring. After 64 hours of heating at 90C., the curing was not complete so 1.5 gm. PCl was stirred into the mixture. After 3 hours of heating at 135C., the sample was hard and clear when cooled. The sample is immediately self-extinguishing by test ASTM D-635.

EXAMPLE 23 Amixture similar to that of Example 22 was made using 20 gm. of Epon 828 resin and 4 gm. of PCI;,. The mixture was cured by heating for 2 hours at 130C. The product was immediately self-extinguishing.

EXAMPLE 24 3 parts by weight of PCl (solid powder) were thoroughly mixed into 13.6 parts by weight Epon 828 resin. After 5 minutes of stirring at 80C. a clear solution resulTed. The curing conditions included 60 hours at 90C., 8 hours at l25to 155C. and 16 hours at 155C. The product was found to be immediately selfextinguishing by D-635 tests.

EXAMPLE 25 EXAMPLE 26 Example 23 was repeated but 5 gm. of phosphorus oxychloride was used instead of 4 gm. of PCI The cured product was immediately self-extinguishing.

EXAMPLES 27 to 34 Example 25 was repeated 8 times, except that the linear PNC1 polymer was replaced with 5 parts (PNCIQ 4.3 parts cyclic P N F Cl 8.5 parts cyclic P N Br 3.5 parts cyclic (PNF 6 parts cyclic P N Br Ch, 3.5 parts cyclic (PNF 8 parts Cl PNPCh, and parts Cl[PNCl PCl respectively. The cured products were immediately self-extinguishing.

EXAMPLE 35 Example 17 was repeated to obtain two cured samples. Each sample was ground into particles having a mean diameter of about 100 microns. 40 grams of each ground sample was admixed with 60 grams of polyester resin A, one gram of Luperson DSW (a 50 percent solution of methylethyl ketone peroxide), 0.] gram of cobalt octoate (12 percent cobalt) and 0.1 gm. of dimethyl aniline. Polyester resin A was prepared from propylene glycol and a mixture of maleic acid and phthalic anhydride (50/50 on a mole basis). Cures of each sample occurred at ambient conditions. After 8 hours of standing, the two polyester samples were selfextinguishing by the ASTM D-635 test.

EXAMPLE 36 A reaction product of PCl -epoxy resin (Epon 828) was obtained from 1 mole (137.5 gm. PCl and about 400 gm. of the epoxy resin. The liquid reaction product was obtained by slow combination of the components associated with cooling. Otherwise the exothermicity of the reaction would result in curing to a solid product. (In some cases, a solid can be ground to a powder which can then be blended with other particulate or liquid resins. At present the liquid reaction product is preferred for blending into polyurethanes, novolaks, epoxies and polyesters.) One part of the Epon 828-PCl re- EXAMPLE 37 A prepolymer was prepared as in Example 36, but 400 gm. of Epon 828 and 163.5 gm. of POCL, (instead of PCl was used. One part of the liquid prepolymer was mixed with three parts of diethylene glycol-tolyene diisocyanate reaction product (in a liquid stage). The mixture was cured as in Example 36. The cured mixture (resin) was self-extinguishing by ASTM D-635.

EXAMPLE 38 A prepolymer was prepared as in Example 36. but 400 gm. of Epon 828 and 209 gm. of PCl,-, (instead of PCl was used. A solid product resulted. One part of the product the product was ground to a powder (5 micron=ave. particle diameter) and then blended with two parts of novolak resin. The mixture was placed in a mold and cured at 200C. for 1 minute. The cured product was burn-resistant by ASTM D-635.

What is claimed is:

l. A solid polymeric fire-retardant additive consisting essentially of the reaction product of (a) a member of the group consisting of cyclic (PNX where X is a hal ogen atom and y is at least 3 and linear X(PNX ),,PX, where X is a halogen atom and y is at least 1; and (b) a compound containing at least two oxirane groups, the equivalent ratio of (a) to (b) being in the range 0.1-2.011 .0 respectively.

2. A process for preparing a solid polymeric fireretardant additive comprising the steps of:

l. admixing a. a member of the group consisting of cyclic (PNX where X is a halogen atom and y is at least 3 in combination with a trace amount of-a catalytic member of the group consisting of a quaternary hydroxide and quaternary salt and linear X(PNX ),,PX where X is a halogen atom and y is at least 1, and

b. a compound containing at least two oxirane groups, the equivalent ratio of (a) to (b) being in the range 0.l-2.0:l.0 respectively, and

2. heating said admixture at a temperature between about 0 to 250C whereby material (a) cures said compound (b) thus forming a fire-retardant additive. 

1. A SOLID POLYMERIC FIRE-RETARDANT ADDITIVE CONSISTING ESSENTIALLY OF THE REACTION PRODUCT OF (A) A MEMBER OF THE GROUP CONSISTING OF CYCLIC (PNX2)Y WHERE X IS A HAOGEN ATOM AND Y IS AT LEAST 3 AND LINEAR X(PNX2)YPX4 WHERE X IS A HALOGEN ATOM AND Y IS AT LEAST 1; AND (B) A COMPOUND CONTAINING AT LEAST TWO OXIRANE GROUPS, THE EQUIVALENT RATIO OF (A) TO (B) BEING IN THE RANGE 0.1-2.0:1.0 RESPECTIVELY.
 2. A process for preparing a solid polymeric fire-retardant additive comprising the steps of:
 2. heating said admixture at a temperature between about 0* to 250*C whereby material (a) cures said compound (b) thus forming a fire-retardant additive. 